title: Phylogenetic relationships and Y genome origin in Elymus L. sensu lato (Triticeae; Poaceae) based on single-copy nuclear Acc1 and Pgk1 gene sequences.
abstract: To estimate the origin and genomic relationships of the polyploid species within Elymus L. sensu lato, two unlinked single-copy nuclear gene (Acc1 and Pgk1) sequences of eighteen tetraploids (StH and StY genomes) and fourteen hexaploids (StStH, StYP, StYH, and StYW genomes) were analyzed with those of 35 diploid taxa representing 18 basic genomes in Triticeae. Sequence and phylogenetic analysis suggested that: (1) the St, H, W, and P genomes were donated by Pseudoroegneria, Hordeum, Australopyrum, and Agropyron, respectively, while the Y genome is closely related to the Xp genome in Peridictyon sanctum; (2) different hexaploid Elymus s.l. species may derived their StY genome from different StY genome tetraploid species via independent origins; (3) due to incomplete lineage sorting and/or hybridization events, the genealogical conflict between the two gene trees suggest introgression involving some Elymus s.l. species, Pseudoroegneria, Agropyron and Aegilops/Triticum; (4) it is reasonable to recognize the StH genome species as Elymus sensu stricto, the StY genome species as Roegneria, the StYW genome species as Anthosachne, the StYH genome species as Campeiostachys, and the StYP genome species as Kengyilia. The occurrence of multiple origin and introgression could account for the rich diversity and ecological adaptation of Elymus s.l. species.
authors.affiliation: Triticeae Research Institute, Sichuan Agricultural University, Chengdu 611130, Sichuan, China; Key Laboratory of Crop Genetic Resources and Improvement, Ministry of Education, Sichuan Agricultural University, Chengdu 611130, Sichuan, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Fan
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Sha
authors.forename: Zhen-Zhen
authors.initials: ZZ
authors.lastname: Dong
authors.forename: Hai-Qin
authors.initials: HQ
authors.lastname: Zhang
authors.forename: Hou-Yang
authors.initials: HY
authors.lastname: Kang
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Chun-Bang
authors.initials: CB
authors.lastname: Ding
authors.forename: Rui-Wu
authors.initials: RW
authors.lastname: Yang
authors.forename: You-Liang
authors.initials: YL
authors.lastname: Zheng
authors.forename: Yong-Hong
authors.initials: YH
authors.lastname: Zhou
mesh_terms: D001499:Bayes Theorem; D002467:Cell Nucleus / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D031749:Elymus / Q000145:classification* / Q000235:genetics; D019143:Evolution, Molecular; D018745:Genome, Plant; D016013:Likelihood Functions; D010802:Phylogeny; D011123:Polyploidy; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D018744:DNA, Plant
keywords: Acc1; Elymus L. sensu lato; Genome origin; Pgk1; Phylogenetic relationships